Tire circumferential phase identification method and tire

Abstract

The present application relates to the field of tire manufacturing and detection technology, and specifically discloses a tire circumferential phase identification method and a tire. The present application obtains the angle θT of the tread joint in the circumferential direction at the tire forming stage; the RFID chip is attached to the position θR maintaining a preset angle difference Δ with θT, θR=(θT+Δ)mod360°; Δ is associated and bound with the RFID chip coding; during subsequent detection, Δ is called by reading the RFID coding, the position θT of the tread joint is inversely calculated as θT=(θR-Δ)mod360°, and the position is associated with the detection data. The present application expands the RFID chip from a simple identity identification to a tire circumferential phase reference, without manually searching for the joint or relying on the easily failed appearance mark, the detection and analysis efficiency is improved by more than 90%, and only one RFID chip is needed for each tire, which is low in cost and easy to mass produce and implement.

Description

Technical Field

[0001] This invention relates to the field of tire manufacturing and testing technology, specifically a method for accurate identification of the circumferential phase of tire tread joints based on RFID chips, and a tire manufactured using this method. Background Technology

[0002] Tires are multi-layered rubber composite products, with components such as the tread, belt layer, carcass ply, inner liner, sidewall, and bead typically bonded together in a specific order on molding equipment. The joints of these components in the circumferential direction can create localized differences in thickness, stiffness, mass, or material continuity. These differences can affect tire uniformity, radial force ripple (RFV), lateral force ripple, dynamic balance, out-of-roundness, and tire noise.

[0003] The tread joint is one of the locations most prone to local structural variations in the circumferential direction. Near the tread joint, there may be changes in rubber overlap thickness, joint compaction, local stiffness, or mass distribution. For certain specifications or process conditions, the location of the tread joint may exhibit a statistical correlation with the peak, trough, or harmonic phase of the RFV curve. Therefore, accurately determining the tread joint's position in the tire's circumferential direction is crucial for tire inspection and process optimization.

[0004] Currently, RFID chips are used in tires for identification and logistics tracking. However, the chip's placement is usually only considered for readability and structural safety, and there is no definitive correspondence between its circumferential position and the tread joint. Existing technologies mainly use three methods to determine the tread joint position: first, visual marking at the tread joint, but these markings are prone to wear and detachment; second, inferring the joint position from a detection curve (such as an RFV waveform), but tire performance is affected by many factors, making the inference unreliable; and third, manually locating the joint, which is inefficient and prone to errors.

[0005] Furthermore, although Michelin's patent application CN119234135A proposes to measure the angular relationship between physical markers through image recognition, this scheme relies on the physical colored dots already present on the vulcanized tire, which is a post-measurement, and RFID is only used to store the results and is not given the function of circumferential phase identification.

[0006] Therefore, existing technologies generally suffer from the problem of RFID chips being out of sync with the process and the difficulty in automatically tracing the position of tire tread joints. Summary of the Invention

[0007] This invention aims to solve the problem that RFID chips in the prior art can only be used for identification and cannot be used as a circumferential phase reference. It provides a method and a tire that can establish the circumferential phase correspondence of the tread joint using only one RFID chip in each tire, thereby achieving low-cost, batch-implementable phase traceability and automatically associating the tread joint position with detection data such as uniformity and dynamic balance.

[0008] To solve the above technical problems, the present invention provides a tire circumferential phase marking method, the method comprising the following steps:

[0009] S1. During the tire forming stage, obtain the first angle information θT of the tread joint in the circumferential direction;

[0010] S2. Attach the RFID chip to a second angular position θR that maintains a preset angular difference Δ with the first angular information θT, and associate and bind the preset angular difference Δ with the code of the RFID chip, where θR=(θT+Δ)mod360°;

[0011] S3. In subsequent testing, the preset angle difference Δ is called by reading the code of the RFID chip, and the position of the tread joint θT=(θR-Δ)mod360° is determined according to the second angle position θR and the preset angle difference Δ.

[0012] Preferably, the preset angle difference Δ in S2 is 0°.

[0013] Preferably, the preset angle difference Δ in S2 is 180°.

[0014] Preferably, the preset angle difference Δ in S2 is any fixed value among 30°, 60°, 90° or 120°.

[0015] Preferably, in S2, the RFID chip is attached to the outer surface of the tire's inner liner, between the tire carcass ply and the inner liner, in the tire sidewall area, or near the tire bead.

[0016] Preferably, in S1, the first angle information θT of the tread joint is identified by a photoelectric sensor or vision system on the forming drum to identify the leading edge of the tread end, and the angle value is recorded by an encoder or PLC.

[0017] Preferably, the error between the bonding angle of the RFID chip and the target angle in S2 is controlled within ±5°.

[0018] Preferably, the subsequent tests in S3 include at least one of uniformity testing, dynamic balance testing, out-of-roundness testing, X-ray testing, visual inspection, or road testing; after determining the tread joint position θT, the tread joint position is correlated with the test data.

[0019] Preferably, the first angle information θT in S1 is the tread joint process reference angle recorded during the tire forming stage, rather than the apparent joint position formed by the flow displacement of the rubber material after vulcanization.

[0020] On the other hand, the present invention also provides a tire that is manufactured and marked using the above-described tire circumferential phase marking method.

[0021] The beneficial effects of this invention are:

[0022] 1. The tire circumferential phase identification method of this invention extends the RFID chip from a simple identification to a circumferential phase reference for the tire, realizing a functional leap from "identity traceability" to "phase traceability." This phase reference is based on the angle recorded during the molding stage and is unaffected by the flow of rubber material after vulcanization or wear of appearance markings, avoiding information loss due to wear, contamination, or detachment of appearance markings. It provides a stable and reliable circumferential reference for quality traceability throughout the entire lifecycle of a single tire. After reading the RFID code, not only can the tire's identity information be known, but the circumferential position of the tread joint can also be determined through the correspondence between the chip and the tread joint. This allows for direct linking of detection data (such as RFV waveforms and dynamic balance angles) with specific process characteristics. This invention establishes the actual process joint phase first, and then analyzes the phase difference between the detection curve and the joint, making the judgment more reliable. It solves the problem in existing solutions where the joint position is inferred from the detection curve, easily leading to misjudgments of waveform anomalies caused by equipment, molds, belt layers, and other factors as tread joint anomalies.

[0023] 2. The tire circumferential phase identification method of this invention can significantly improve analysis efficiency. Currently, manually locating tire tread joints takes an average of about 60 seconds per tire and is prone to errors. With this invention, the detection equipment automatically reads the RFID and associates the phase information, taking an average of about 5 seconds per tire. Based on a batch of 1000 tires, the analysis time can be reduced from approximately 16.7 hours to approximately 1.4 hours, a reduction of approximately 91.7%. In a scenario of quality sampling of 200 tires, manual searching and data entry takes about 3.3 hours, which is reduced to less than 0.3 hours with this invention.

[0024] 3. The tire circumferential phase identification method of this invention, used to identify the circumferential phase of a tire, or the tires manufactured using this method, has the advantages of low cost and ease of mass production. Each tire requires only one RFID chip, without significantly altering the existing tire structure and molding process. Equipment modification is minimal, making it suitable for large-scale production. By long-term collection of RFID phase, tread joint phase, and detection curve phase, the influence of the tread joint on the first and second harmonics of RFV, the dynamic balance center of gravity angle, and the high point of out-of-roundness can be statistically analyzed, thereby guiding the design of the tread joint angle, the joint compaction process, the arrangement of component misalignment angles, and the optimization of the molding process.

[0025] The essence of this invention is to reconstruct the RFID chip from an identification identifier into a digital circumferential phase reference for the tire by establishing a fixed circumferential phase relationship between the chip and the tread joint. This is a fundamental leap in function, rather than a simple adjustment of physical position.

[0026] Instruction manual illustrations

[0027] To more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram showing the tire's circumferential direction. The diagram indicates the tread joint angle θT, the RFID chip contact angle θR, the angle difference Δ, and the circumferential direction from 0° to 360°. Figure 1 The θT=72° marked in the figure is only an illustrative angle used to illustrate the circumferential phase correspondence between the tread joint and the RFID chip, and does not constitute a limitation on the specific implementation angle.

[0029] Figure 2 This is a radial cross-sectional view of the tire, showing the area where the RFID chip is attached to the tire sidewall. This location does not constitute a limitation on the specific attachment position. Among them, 1-RFID chip, 2-carcass ply, 3-inner liner, 4-triple composite, 5-triangle rubber, 6-bead.

[0030] Figure 3 This is a flowchart illustrating the entire process from tire production to testing using the present invention. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1: Δ=0° (the chip and the tread connector correspond at the same angle)

[0033] This embodiment uses a 205 / 55R16 tire as an example for illustration. This embodiment combines... Figure 3 The technical solution of the present invention will be described in detail below.

[0034] A method for tire circumferential phase marking, the method comprising:

[0035] S1. In the tread bonding process, the leading edge of the tread compound is detected by a photoelectric sensor. The PLC control system reads the angle value of the encoder of the forming drum at this time and records it as θT = 126.0°.

[0036] S2. Set the RFID chip and the tire tread connector to correspond at the same angle, i.e., Δ = 0°. Then the chip bonding angle θR = (126.0° + 0°) mod 360° = 126.0°.

[0037] The control system drives the servo motor of the forming drum to rotate, and the encoder provides closed-loop feedback on the angle position. When the forming drum rotates to 126.0° (allowable error ±5°), it triggers the bonding head to bond the RFID chip to the tire tread joint position. The measured bonding angle θR' = 127.8°, with an error of +1.8°, meets the process requirements.

[0038] After the tire blank is vulcanized, the chip code is read using a handheld or fixed RFID reader to obtain "EPC-2026-000126". In the MES database, this code is associated and bound with information such as θT=126.0°, Δ=0°, tire specifications, production machine, mold number, etc.

[0039] S3. At the uniformity inspection station, the RFID reader built into the inspection equipment reads the tire code "EPC-2026-000126" and queries the MES database through the local area network to obtain the corresponding Δ=0° for the tire. The inspection equipment uses the 0° phase on its inspection spindle as a reference to identify the actual position of the chip as approximately 127.8° (this value is only used to verify the bonding tolerance and does not affect the determination of the joint reference angle).

[0040] Based on θT = (θR - Δ) mod 360°, the tread joint position is calculated to be the reference angle θT = 126.0° recorded during the molding stage. The testing equipment automatically marks the tread joint position on the measured RFV waveform curve. The results show that the first-order peak angle of RFV is approximately 132.0°, which differs from the tread joint reference angle of 126.0° by about 6.0°. Based on this, the quality engineer can quickly determine that the first-order fluctuation peak of RFV in this batch of tires deviates from the tread joint position by approximately 6°, and the compaction pressure, overlap, or cut length control of the tread joint should be the focus of the investigation.

[0041] Results Verification: Using the method of this embodiment, the phase correlation analysis time for each batch of 1000 tires is approximately 1.4 hours (calculated at 5 seconds per tire), which is about 91.7% less than the approximately 16.7 hours (calculated at 60 seconds per tire) for manually locating the tread joint.

[0042] Example 2: Δ=180° (chip located on the opposite side of the tire tread joint)

[0043] This embodiment is basically the same as Embodiment 1, except that the preset angle difference Δ = 180°. Applicable scenarios: There is a stress concentration area or abrupt thickness change area directly below the tread joint, which is not suitable for direct bonding of chips.

[0044] Taking θT=45° as an example, then θR=(45°+180°) mod 360°=225°. The RFID chip is attached to the 225° position, and Δ=180° is recorded in the database.

[0045] During subsequent testing, the device reads the chip position θR (e.g., measured 224.5°) and calculates θT = (224.5° - 180°) mod 360° = 44.5°.

[0046] This solution also achieves accurate phase tracking while avoiding weak areas in the joint's local structure. It is suitable for scenarios where there are stress concentration zones beneath the tread joint.

[0047] To ensure the reliability of phase analysis, this invention preferably controls the error between the RFID chip bonding angle and the target angle θR within ±5°, which can be relaxed to ±10° in ordinary traceability scenarios. The ±5° tolerance is achieved through the following combined methods:

[0048] (1) Encoder resolution: preferably not less than 4096 pulses / revolution, corresponding to a theoretical angular resolution of about 0.088°;

[0049] (2) Joint identification error: The photoelectric sensor or vision system identifies the leading edge of the tread, and the error is preferably controlled within ±1°;

[0050] (3) Mechanical bonding error: The PLC or servo system triggers the bonding head within the target angle window, and the mechanical error is preferably controlled within ±2°;

[0051] (4) Random inspection and verification: After bonding, random inspection is carried out using a camera or angle ruler;

[0052] (5) Vulcanization correction: For the apparent joint offset caused by the flow of rubber after vulcanization, correction coefficients can be established for different specifications, but the phase reference is still based on the angle recorded in the molding stage.

[0053] In other embodiments of the present invention, the method described above, which uses the tread joint as a phase reference, can also be extended to other process joints of tires. For example, a fixed circumferential phase correspondence can be established between the RFID chip and the belt layer joint, the ply layer joint, or the sidewall joint to achieve a similar phase traceability function. Additionally, if the detection equipment cannot directly identify the chip angle through the RFID reader, auxiliary visible marks, magnetic marks, or QR codes can be set near the chip's contact point. RFID is used for identification binding, and the auxiliary marks are used for angle alignment; the combination of both can also achieve tread joint position traceability.

[0054] 1. Compared to RFID solutions used only for identification, this invention adds a circumferential phase attribute. After reading the RFID tag, not only can the tire's specifications, batch number, and identity be determined, but also the position of the tread joint relative to the tire's detection angle reference can be identified.

[0055] 2. Compared with the appearance marking scheme, the present invention binds the tread joint phase information to the RFID code and database, which does not rely on the appearance marking for long-term visibility and avoids position loss caused by painting, trimming, pollution and wear.

[0056] 3. Compared with the reverse calculation method based on the detection curve, the present invention first establishes the actual process joint phase, and then analyzes the phase difference between the detection curve and the tread joint, which can reduce the risk of misjudging equipment, mold, belt layer or tire body factors as tread joint factors.

[0057] 4. Compared with multi-chip or multi-tag schemes, the present invention still maintains one RFID chip per tire, with less structural disturbance and less cost increase, making it suitable for mass production.

[0058] Scenario 1: Analysis of the First Harmonic Contribution of RFV

[0059] Without the method of this invention, analyzing the phase relationship between the tread joint and the first-order peak value of RFV typically requires manually locating the tread joint, manually recording the angle, and then matching it with the detection curve. Based on an average of 60 seconds per joint for manual locating and recording, and a batch size of 1000 joints, this process takes approximately 16.7 hours per batch. With this invention, the detection equipment reads the RFID code and automatically retrieves the tread joint phase. Based on a system matching time of 5 seconds per joint, this process takes approximately 1.4 hours per batch, reducing the overall process time by about 91.7%. This data is a process calculation value, which can be further confirmed by companies through on-site cycle time measurements.

[0060] The technical significance of this invention lies in the fact that it does not simply improve the RFID reading rate, but rather binds the tread joint phase to the RFV detection curve, allowing the difference between the first-order peak angle and the tread joint angle to be statistically analyzed in batches. For example, if the proportion of RFV first-order peak values ​​falling within ±15° of the tread joint in 1000 tires of a certain specification is significantly higher than that of random distribution, then the tread joint overlap, joint compaction, and tread length control can be prioritized for investigation.

[0061] Scenario 2: Closed-loop process adjustment

[0062] When using ordinary RFID identification, quality personnel can only associate RFV anomalies with tire numbers, machines, and molds, making it difficult to quickly confirm whether the anomalies are concentrated near the tread joint phase. With this invention, the system can automatically output the difference distribution between the "tread joint angle and the detected anomaly angle," helping to determine whether adjustments to the tread joint compaction pressure, joint overlap, cut length, or the misalignment angle between the tread joint and other component joints are needed.

[0063] Based on the calculation that 200 tires need to be sampled for each quality analysis, manually locating the joint and entering data would take approximately 3.3 hours. This invention can reduce this step to less than 0.3 hours, allowing quality personnel to spend their main time on root cause analysis and process testing, rather than location searching. This effect needs to be confirmed by actual measurements in conjunction with the actual testing system cycle time in the work area.

[0064] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for tire circumferential phase marking, characterized in that, The method includes the following steps: S1. During the tire forming stage, obtain the first angle information θT of the tread joint in the circumferential direction; S2. Attach the RFID chip to a second angular position θR that maintains a preset angular difference Δ with the first angular information θT, and associate and bind the preset angular difference Δ with the code of the RFID chip, where θR=(θT+Δ)mod360°; S3. In subsequent testing, the preset angle difference Δ is called by reading the code of the RFID chip, and the position of the tread joint θT=(θR-Δ)mod360° is determined according to the second angle position θR and the preset angle difference Δ.

2. The tire circumferential phase marking method according to claim 1, characterized in that, The preset angle difference Δ in S2 is 0°.

3. The tire circumferential phase marking method according to claim 1, characterized in that, The preset angle difference Δ in S2 is 180°.

4. The tire circumferential phase marking method according to claim 1, characterized in that, The preset angle difference Δ in S2 is any fixed value among 30°, 60°, 90° or 120°.

5. The tire circumferential phase marking method according to claim 1, characterized in that, In S2, the RFID chip is attached to the outer surface of the tire's inner liner, between the tire carcass ply and the inner liner, in the sidewall area, or near the tire bead.

6. The tire circumferential phase marking method according to claim 1, characterized in that, In S1, the first angle information θT of the tread joint is identified by the photoelectric sensor or vision system on the forming drum to identify the leading edge of the tread end, and the angle value is recorded by the encoder or PLC.

7. The tire circumferential phase marking method according to claim 1, characterized in that, The bonding angle error of the RFID chip in S2 is controlled within ±5°.

8. The tire circumferential phase marking method according to claim 1, characterized in that, The subsequent tests in S3 include at least one of uniformity testing, dynamic balance testing, out-of-roundness testing, X-ray testing, visual inspection, or road testing; after determining the tread joint position θT, the tread joint position is correlated with the test data.

9. A tire circumferential phase marking method according to claim 1, characterized in that, The first angle information θT in S1 is the reference angle of the tread joint process recorded during the tire forming stage, rather than the apparent joint position formed by the flow displacement of the rubber material after vulcanization.

10. A tire, characterized in that, The tire circumferential phase marking method according to any one of claims 1-9 is used for production and marking.

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